Question : Can the "My SharePoint Sites" web part membership be identified using Active Directory groups instead of individual users?

While working with the My Sites web parts, I've noticed that the "My SharePoint Sites" web part requires the user to be explicitly added to the site's Membership group for the web part to populate as expected.  Now, if I only add Active Directory groups that the user is a member of to the SharePoint Membership group, the web part does not populate with the user's membership information.  

Is it a requirement that the user be explicitly added to the 'Site Name' Membership group?  Can MOSS not recognize that the user is a member of the group for the "My SharePoint Sites" web part?

Answer : Can the "My SharePoint Sites" web part membership be identified using Active Directory groups instead of individual users?

that is correct... if you use a AD Group, you lose the user-level details...
there are 3rd party tools that make it easier to manage sharepoint users... so that you don't have to resort to adding users based on AD Groups...
http://store.bamboosolutions.com/ps-46-6-user-management-solution-accelerator.aspx